Jumps that take you out of bounds or off the map are exploits. Jumps like the one that takes you through the middle of Ally barrier along the ramp are in more of a grey area. Some people would consider it an exploit, others would say 'clever girl'. My policy is to know all the jumps and be able to chase anyone down who's using them.
In some extreme cases I have matched the enemy in taking the flag out of bounds, but I would only ever do that after they have proven to brazenly exploit and you gotta match fire with fire. Still, I could have just as easily been reported and there would be no recourse.